TOULOUSE, France — Tour de France riders have already battled crashes, flares, and fans or dogs straying into their roads. Now, some ne’er-do-well dumped tacks on the road, and if the aim was to disrupt cycling’s big race, it worked.

But as cyclists often do in the face of difficulty, they kept going.

Bradley Wiggins of Britain, the Queen Bee of the pack because he is wearing the yellow jersey, drew plaudits for at least slowing its pace and waiting for defending champ Cadel Evans in Sunday’s Stage 14.

Tour officials estimated that around 30 competitors in the main pack blew flats near the day’s steepest climb, the Mur de Peguere, as Luis Leon Sanchez led a breakaway far ahead of the trouble to win the stage. One rider crashed as a result of the tacks.

French police — who line the course route by the hundreds for crowd control each stage — were investigating the rare if not unprecedented, incident in a sport already saddled with issues from doping to crashes.